Investigation of Effect of Heterovalent Element Doping on Ionic Conductivity in Li₃InCl₆ System Using Neural-network Potential

Abstract

For the halide solid electrolyte Li₃InCl₆, which has both high water resistance and high ionic conductivity, doping with different elements to further increase the conductivity is attracting attention. In this study, we investigated co-doping Li₃InCl₆ with Nb⁵⁺ and Zr⁴⁺. A pretrained neural-network potential was used for molecular dynamics simulations, and the results indicated that doping with a high concentration of Zr⁴⁺ and low concentration of Nb⁵⁺ promotes disorder in the Li⁺/vacancy arrangement on the diffusion path, even at relatively low temperatures. Bayesian optimization revealed the optimal composition with fewer samples, highlighting its utility for exploring complex compositions and expensive experimental investigations.